Edita Malčiauskienė, *Algirdas Milašius, Weave Factor for Seam Slippage Prediction Rimvydas Milašius of Unbalance Fabrics Kaunas University of Technology, Abstract Department of Textile Technology In this article the seam slippage characteristics of unbalanced weave fabrics are analysed. Studentu Str. 56, LT-51424 Kaunas, Lithuania The slippage resistance of yarns at a seam in woven fabrics is a very important factor, E-mail: [email protected] and strong claims have been made about this property. Preliminary investigations showed that balanced and unbalanced woven fabrics must be estimated differently. Well-known *JSC „Drobė Co“, factors such as the fabric structure factor P and average float F were investigated, and Draugystės str. 14, LT-51259, Kaunas, Lithuania then a new fabric structure factor, NPR, was proposed, which best characterises the weave from a thread slippage point of view. According to the coefficient of determination, it was found that the power equation of the new weave factor for balanced fabrics shows good correlation between experimental and theoretical values. It was proved that seam slippage influences not only the weave factor in the slip direction but also in the normal direction. The weave factor in the slip direction influences seam slippage by 81%, the weave factor in opposite direction – 19%. However, this new model is unsuitable for describing warp and weft ribs from a thread slippage point of view because they comprise a separate group of weaves, with particular theories applying to them. Key words: woven fabrics, weave factor, seam slippage, fabric structure. erley theory. In the first case it is a ratio rib 4/4, giving the same value, P = 1.205. of the surface covered by threads to the Later V. Milašius proposed factor P1, cal- total fabric area. In the second case it is culated in the warp direction [1, 9], cov- a ratio of the setting of the “square” ana- ering most of the weaves used. logue of a given fabric to the setting of standard “wire” plain weave fabric [4, 5]. In a previous work it was proved that the This group also includes the average float properties of fabrics with the same set- length F, which was proposed by Ashen- ting parameters, woven with not identi- hurst, and the weave factor P, proposed cal technological parameters, are differ- by V. Milašius. ent [10]. Therefore, all fabrics need to be woven with the same loom. In this way, The average float length F was a very only the weight of the fabric weave can simple and widely used factor [6]. Later be analysed. it was observed that this factor did not describe all the properties of a weave The slippage resistance of yarns at a seam which are important from a technologi- in woven fabrics is a very important fac- cal and end-use point of view. This factor tor, and strong claims are made for this could not evaluate the differ ence between property. It is necessary to know how the types of weaves (it is well known that the fabric structure influences seam slippage n Introduction weaves twill 7/1, satin 8/3 and panama quality before manufacturing the fabric. The structure of woven fabric is complex 4/4 have a different tight ness, but are still However, the slippage of seams depends be cause in its evaluation we need to take counted with the same value, F = 4) and on some different factors, for example into consideration many woven fabric unbalanced weaves, whose average warp the structure of ready-made cloths and structure parameters, such as warp and float is different from the average weft the fitting of the cloth to the human body. weft materials, the warp and weft linear float (warp rib 4/4 and weft rib 4/4 be- Moreover, knowledge of the dependence density, warp and weft settings and the have very differently during weaving but on the woven fabric structure is very im- fabric weave [1 - 3]. All these woven fab- are still evaluated using the same value, portant for practical purposes because it ric structure parameters can be evaluated F = 2.5). allows to design fabric with new patterns together as well as separately, but woven suitable for clothing that will not slip in fabric weave evaluation is the most com- The weave factor P proposed by V. the seams. Seam slippage is a measure plex because it is important to consider Milašius [7] is calculated directly from of the ability of warp yarns to slip over the nature of the float, its arrangement, the weave matrix. Factor P evaluates not weft ones near the seam, which extends the in terlacing of adjacent threads etc. only a single thread float, but also an in- in the warp direction, when the fabric is All seven parameters of the fabric struc- terlacing of adjacent threads and can be subjected to a given load in the weft di- ture can be evaluated by integrated fabric calculated for all types of weaves. The rection (and vice versa). This load is ap- structure factors. Various scientists have weave factor P is a measure of the fabric plied so as to separate the two pieces of proposed different evaluations of all structure, describing some of its proper- the fabric joined by a seam, and thus an these fabric parameters. Ac cording to the ties, such as elasticity, air permeability, opening, which is the result of yarn slip- methods of evaluation of these param- among others [8]. Although factor P is page, appears near the seam. It is an im- eters, two groups of integrat ed factors very good for balanced weaves, it cannot portant parameter for fabric characterisa- are distinguished: the first is based on the evaluate the differ ence between unbal- tion, especially for garment production. Peirce theory and the second on the Bri- anced weaves – warp rib 4/4 and weft The dependence of seam slippage values Malčiauskienė E., Milašius A., Milašius R.; Weave Factor for Seam Slippage Prediction of Unbalance Fabrics. 101 FIBRES & TEXTILES in Eastern Europe 2011, Vol. 19, No. 4 (87) pp. 101-104. Figure 1. Weaves used in the experiments: 1 – broken twill 1/2 B, 2 – broken twill 1/2 A, 3 – warp rib 2/1, 4 – negative broken in warp twill 2/1, 5 - negative broken in warp twill 2/2, 6 - warp rib 2/2, 7 - warp rib 3/3, 8 - warp rib 3/1, 9 - negative broken in weft twill 2/1, 10 – weft rib 2/1, 11 - negative broken in weft twill 2/2, 12 – weft rib 2//2, 13 – weft rib 3/1, 14 – weft diagonal 3,2,1,3,2,1, 15 – warp diagonal 3,2,1,3,2,1, 16 - warp diagonal 4,1,4,3, 17 – warp crepe, 18 – soleil weave, 19 – corkscrew 3/3 (in weft), 20 - corkscrew 3/3 (in warp), 21 – weft crepe, 22 – weft diagonal 4,1,4,3. on the fabric weave makes this property diction which can be used for unbalanced slippage of woven fabrics”) at a 78 N an interesting case for study. weave fabrics. force distance between yarns after the slippage has been measured. Many studies have been performed on n the slippage of the yarns of woven fabric, Materials and methods Pieces of the test fabric were sewn to- but this question is still open [11 - 15]. Unbalanced weave fabrics were woven gether using a stitch type 301 (see Fig- The influence of weave on the slippage of for the investigations, which differed ure 2). 100% polyester core spun of lin- ear density 45 tex was used for the seam, yarns of woven fabric has still not been only in the weave. They were allwoven with a stitch density of 50 dm-1 and nee- completely investigated. on rapier looms from the same back rest. Therefore all the fabrics were woven dle size of 0.90 mm. The test specimens with the same setting and technological were stretched until a force of 200 N. In a previous work [16] we stated that Five specimens of each fabric were pre- parameters. They all had the same lin- the relationship between well-known pared for the tests. structural models and weave factors are ear density of the warps and wefts – 12.5 tex×2, warp setting - 300 dm-1, and problematic and ambigous, and therefore In this research only tests of seam slip- weft – 260 dm-1. The weaves were cho- we made an attempt to find a new weave page in the weft direction were carried sen so that they could be woven at the factor which best characterizes the fab- out (warp yarns slipping over weft yarns). same loom settings (see Figure 1). ric structure from a thread slippage point All results were statistically processed. of view. Preliminary investigations with The slippage resistance of yarns at a seam The new weave factor, NPR, [16] was balanced woven fabrics showed that the of the woven fabrics was measured with a calculated as a proportion of all the new weave factor, NPR, better describes tensile testing machine - Zwick/Z005, ac- the influence of weave on slippage than threads resisting slippage to the warp and cording to the international standard “De- weft repeats (Equation 1): other known weave factors (V. Milašius termination of the slippage resistance of factor P or Ashenhurst factor F). yarns at a seam in woven fabrics – Part 1: ∑ i NPR = (1) Fixed seam opening method” (LST EN R1 R2 The aim of this work was to determine a ISO 13936-1: 2004), and according to the new weave factor, NPR, for slippage pre- Woolmark test method (TM 117 “Seam where: ∑ i − is the sum of all threads resisting slippage, R1 - warp repeat, R2 - weft repeat.